Synthesis of a novel phosphorus-nitrogen-containing intumescent flame retardant and its application to fabrics

• A novel phosphorus-nitrogen-containing IFR, ditrimethylolpropane di-N-hydroxyethyl phosphoramide (DDP), was successfully synthesized.
• DDP was used as a flame retardant for various fabrics.
• DDP showed high flame retardancy for nylon and moderate flame retardancy for cotton and polyester.

A novel phosphorus-nitrogen-containing intumescent flame retardant (IFR), ditrimethylolpropane di-N-hydroxyethyl phosphoramide (DDP), was successfully synthesized and used as a flame retardant for various fabrics. The chemical structure of DDP was characterized using FT-IR, 1H NMR, 31P NMR, and elemental analysis. The thermal property of DDP was investigated by thermogravimetric analysis. The effect of DDP on the flame-retardant properties of fabrics was evaluated by measurement of the burning length. The optimal synthesis conditions for DDP were determined. DDP showed high flame retardancy when applied to nylon and moderate flame retardancy when applied to cotton and polyester.

In the first, the hydroxyl groups of Di-TMP were esterified with POCl3 at 50 °C to form DDC, which was then hydrolyzed with distilled water at 72 °C to form DDE. Then, the phosphorus-nitrogen IFR, DDP, was formed when DDE was reacted with 2-aminoethanol using boric acid as a catalyst at 72 °C in 1,4-dioxane.Figure optionsDownload as PowerPoint slide